1. Field of the Invention
The field of the invention is mainly that of means to limit the saturation of the tracking unit of a radar.
Such means consist of the association, with each plot, of a piece of information on the estimated validity of the plot.
The obtaining of this piece of information on validity then provides for improved processing of the plot thus "informed" or associated with information. If the piece of information on validity can assume several states, which may be continuous or discontinuous, it is possible, for example, to control the saturation of the tracking unit of the radar in selecting the plots transmitted to it by setting a threshold on the piece of information on validity. In another non-restrictive application of the invention, the information on validity may be used for signature analysis or target recognition.
The plots given by the extractor of a radar are most often formed by the agglomeration of detected echo points, or again "echo presence". The elementary echos are combined, by integration and compacting, to form plots with relatively homogeneous general characteristics. These plots are defined by a number of parameters or attributes such as: the mean distance from the radar, the mean angle of sight, the score (number of constituent elementary echos forming the plot), the maximum amplitude of return (intensity of the echos) or, again, attributes related to the shape of the plot (extension in distance or in azimuth, moment of inertia, etc). Other attributes used, for example are attributes that are inherent to the specific type of radar used.
For its part, the tracking unit in a radar essentially performs a data-processing task, designed to identify tracks, namely to interlink plots corresponding to one and the same echo, or group of echos, during successive sweeps of the radar. Each track is defined, for example, by the previous position of a plot, and a speed vector value of the plot. The tracking of a plot involves, notably, motion-prediction techniques using algorithmic tools (Kalman filtering etc.).
Because it is essentially software, the tracking unit is saturable.
2. Description of the Prior Art
Up till now, the techniques used to control the saturation of the tracking unit have consisted in causing a sudden stoppage of the supply of information coming from the extractor, whenever the processing capacity experiences an overflow. This prior art technique has the drawback of depriving the tracking unit of useful information, arbitrarily and at a time when the wealth of information would rather require the attentive tracking of targets.